In general, refrigerators are home appliances for storing foods at a low temperature state.
Such a refrigerator includes a main body defining a storage compartment and a door movably connected to the main body to open or close the storage compartment.
For example, the storage compartment may be partitioned into a refrigerating compartment and a freezing compartment. The door includes a refrigerating compartment door for opening or closing the refrigerating compartment and a freezing compartment door for opening or closing the freezing compartment. Thus, a user should open the freezing compartment door or the refrigerating compartment door to take foods stored in the refrigerating compartment or the freezing compartment out.
Also, in such a common refrigerator, a portion or the whole of an outer appearance of the refrigerator may be defined by a refrigerator door. Recently, a refrigerator in which a decorative outer panel having various textures and shapes is applied to the main body in addition to the refrigerator door is being spotlighted.
For example, a refrigerator in which a decorative outer panel having a metal texture may be provided on a front surface of the refrigerator, a decorative outer panel on which various patterns are printed is provided, or a front surface thereof is manufactured using an tempered glass or a transparent plastic material is being developed.
Specifically, in recent, a decorative outer panel having a flat plate shape may be provided on a front surface of a refrigerator door and a portion of a refrigerator main body to define an outer appearance of a refrigerator. Such a refrigerator is disclosed in Korean Patent Publication No. 10-2007-0032146.
Here, the decorative outer panel of the refrigerator may have a plate shape, and the decorative outer panel having the plate shape may be manufactured through a casting method which uses a glass plate as a mold. Hereinafter, a method for manufacturing a decorative outer panel of a refrigerator door using the casting method will be described.
FIG. 1 is a perspective view of a mold for manufacturing a decorative outer panel of a refrigerator according to a related art.
Referring to FIG. 1, a decorative outer panel 1 having a plate shape to define an outer appearance of a refrigerator door or a refrigerator main body may be manufactured through a casting method.
A mold 10 for molding the decorative outer panel 1 is constituted by an upper mold 11 and a lower mold 12. A gasket 13 is disposed between the upper mold 11 and the lower mold 12. Also, acrylic monomers which are a material for molding the decorative outer panel 1 may be injected into the mold 10.
Each of the upper mold 11 and the lower mold 12 may be formed of a glass material. This is done for a reason in which the upper and lower molds 11 and 12 should have a smooth surface such as a mirror surface because the decorative outer panel 1 should be smooth, like a glass surface.
The gasket 13 may be disposed around the lower mold 12. The gasket 13 may be formed of a soft PVC material. Also, the gasket 13 may have a shape corresponding to that of the decorative outer panel 1. That is, when the upper mold 11 and the lower mold 12 are coupled to each other, the acrylic monomers are injected into a space defined by the gasket 13. Thus, the decorative outer panel 1 may be molded according to the shape defined by the gasket 13.
Thus, the gasket 13 may be maintained always at a fixed position. For this, a fixing member 20 for fixing the gasket 13 is provided. The fixing member 20 may have a shape similar to tongs or a clamp. The fixing member 20 pushes the gasket 13 to fix the gasket to the lower mold 12.
The upper mold 11 has a size and shape corresponding to those of the lower mold 12. The upper mold 11 has a plane bottom surface. When the upper mold 11 and the lower mold 12 are coupled to each other, the bottom surface of the upper mold 11 contacts the gasket 13.
Thus, after the upper mold 11 and the lower mold 12 are coupled to each other, and then the acrylic monomers are injected into the space defined by the gasket 13, the coupled mold 10 may be polymerized using hot water and steam to mold the decorative outer panel 1.
However, the mold 10 according to the related art may have following limitations.
When the decorative outer panel 1 having the plate shape is molded, since the mold is formed of the glass material in the related art, the general flat-plate shaped decorative outer panel 1 having the smooth surface may be easily molded. However, since the mold 10 formed of the glass material can mold only the flat plate shape having the smooth surface. Thus, it is difficult to mold a decorative outer panel 1 having a three-dimensional pattern or shape on a surface thereof.
Also, when the decorative outer panel 1 is molded using the mold 10 according to the related art, the mold 10 in which the acrylic monomers that is a material for the polymerization and a polymerization initiator are injected is immersed in a hot water bath.
Thus, the hot water bath for the polymerization is heated up to a starting temperature and then is cooled. Also, these processes should be repeatedly performed. For this, the hot water bath should have a size enough to receive the whole mold 10, and the whole water contained in the hot water bath should be adjusted. Thus, fuel costs may be increased, and also, a cycle time may extend.
When the cycle time extends, productivity of the decorative outer wall 1 may be reduced.
Also, according to the related art, one mold 10 has no choice to mold only one decorative outer wall 1. Thus, to produce a plurality of decorative outer panel 1, the manufacturing process should be repeatedly performed as numerous as the number of decorative outer panel 1, or the mold 10 should be provided in number corresponding to the number of decorative outer panel 1. As a result, the productivity may be reduced.
In addition, since the mold for molding the decorative outer panel 1 is formed of the glass material, when the decorative outer panel 1 is mass-produced, a plurality of molds 10 are required. Thus, it may be difficult to manage the mold 10 formed of the glass material, and also, manufacturing costs may be increased.